scholarly journals Removal of Zirconium (Zr) from Aqueous Solution by Polymer Enhanced Ultrafiltration

2021 ◽  
Vol 25 (2) ◽  
pp. 15-21
Author(s):  
O. A Dündar ◽  
Ö. Arar
Keyword(s):  
Aqueous Solution ◽  
Water Soluble ◽  
Molar Ratio ◽  
Efficient Removal ◽  
Solution Ph ◽  
Styrene Sulfonate ◽  
The World ◽  
Interfering Ions ◽  
Sulfonic Acid Groups ◽  
Positively Charged

Although the world output of zirconium has been declining, increasing zirconium consumption cannot compete with this situation. For this reason, removal and recovery of zirconium become important. This work is focused on the removal of Zirconium (as ZrO22+) ions from an aqueous solution using polymer-enhanced ultrafiltration (PEUF) techniques with water-soluble Poly (sodium-p-styrene sulfonate, SSS) sorbent. The negatively charged sulfonic acid groups in the polymer interact with positively charged ZrO22+ cation thereby enabling the efficient removal of ZrO22+through ultrafiltration. The effect of polymer: zirconium mole ratio, initial solution pH, and the presence of interfering ions on the removal of zirconium was investigated. The obtained results demonstrated that ZrO22+ can be removed from the aqueous solution by the PEUF technique with more than 99% efficiency at pH ≥ 2 using polymer: Zr molar ratio of 5:1. The presence of interfering ions did not affect the percent removal of ZrO22+.

scholarly journals Crystal structure of the new hybrid material bis(1,4-diazoniabicyclo[2.2.2]octane) di-μ-chlorido-bis[tetrachloridobismuthate(III)] dihydrate

2015 ◽  
Vol 71 (11) ◽  
pp. 1384-1387
Author(s):  
Marwen Chouri ◽  
Habib Boughzala
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Hydrogen Bonds ◽  
Room Temperature ◽  
Molar Ratio ◽  
Water Molecules ◽  
Site Symmetry ◽  
Two Dimensional ◽  
Slow Evaporation ◽  
Solution Ph

The title compound bis(1,4-diazoniabicyclo[2.2.2]octane) di-μ-chlorido-bis[tetrachloridobismuthate(III)] dihydrate, (C6H14N2)2[Bi2Cl10]·2H2O, was obtained by slow evaporation at room temperature of a hydrochloric aqueous solution (pH = 1) containing bismuth(III) nitrate and 1,4-diazabicyclo[2.2.2]octane (DABCO) in a 1:2 molar ratio. The structure displays a two-dimensional arrangement parallel to (100) of isolated [Bi2Cl10]4−bioctahedra (site symmetry -1) separated by layers of organic 1,4-diazoniabicyclo[2.2.2]octane dications [(DABCOH2)2+] and water molecules. O—H...Cl, N—H...O and N—H...Cl hydrogen bonds lead to additional cohesion of the structure.

scholarly journals Synthesis of Calcium Silicate Hydrate from Coal Gangue for Cr(VI) and Cu(II) Removal from Aqueous Solution

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6192
Author(s):  
Qing Zhang ◽  
Guijian Liu ◽  
Shuchuan Peng ◽  
Chuncai Zhou
Keyword(s):  
Aqueous Solution ◽  
Reaction Time ◽  
Calcium Silicate ◽  
Calcium Silicate Hydrate ◽  
Variable Temperature ◽  
Coal Gangue ◽  
Molar Ratio ◽  
Solution Temperature ◽  
Solution Ph ◽  
Adsorption Temperature

Both the accumulation of coal gangue and potentially toxic elements in aqueous solution have caused biological damage to the surrounding ecosystem of the Huainan coal mining field. In this study, coal gangue was used to synthesize calcium silicate hydrate (C-S-H) to remove Cr(VI) and Cu(II)from aqueous solutions and aqueous solution. The optimum parameters for C-S-H synthesis were 700 °C for 1 h and a Ca/Si molar ratio of 1.0. Quantitative sorption analysis was done at variable temperature, C-S-H dosages, solution pH, initial concentrations of metals, and reaction time. The solution pH was precisely controlled by a pH meter. The adsorption temperature was controlled by a thermostatic gas bath oscillator. The error of solution temperature was controlled at ± 0.3, compared with the adsorption temperature. For Cr(VI) and Cu(II), the optimum initial concentration, temperature, and reaction time were 200 mg/L, 40 °C and 90 min, pH 2 and 0.1 g C-S-H for Cr(VI), pH 6 and 0.07 g C-S-H for Cu(II), respectively. The maximum adsorption capacities of Cr(VI) and Cu(II) were 68.03 and 70.42 mg·g−1, respectively. Furthermore, the concentrations of Cu(II) and Cr(VI) in aqueous solution could meet the surface water quality standards in China. The adsorption mechanism of Cu(II) and Cr(VI) onto C-S-H were reduction, electrostatic interaction, chelation interaction, and surface complexation. It was found that C-S-H is an environmentally friendly adsorbent for effective removal of metals from aqueous solution through different mechanisms.

scholarly journals Treatment of effluent from fertilizer industry by adsorption on willow sawdust-removal of Ni(II) and Cd(II) from the effluent

2021 ◽  
pp. 1-12
Author(s):  
Raafia Najam ◽  
Syed Muzaffar Ali Andrabi
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Low Cost ◽  
Second Order ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
The World ◽  
Pseudo Second Order ◽  
Almost All ◽  
Willow Tree

Sawdust of willow has been investigated as an adsorbent for the removal of Ni(II), and Cd(II) ions from aqueous solution. Since willow tree is widely grown in almost all parts of Kashmir, it can be a common most easily available, sustainable, low cost adsorbent for the treatment of wastewaters in this part of the world where growing industrialization is affecting water quality like elsewhere in the world. Therefore, it is worthwhile to investigate the potential of sawdust of willow tree as an adsorbent for the removal of Ni(II) and Cd(II) ions from aqueous solution as a first step. Batch experiments were conducted to study the effect of some parameters such as contact time, initial concentration of metal ions, solution pH and temperature. Langmuir and Freundlich models were employed for the mechanistic analysis of experimental data obtained. Results reveal that in our system adsorption follows the Langmuir isotherm. The maximum adsorption capacity of Ni(II) and Cd(II) were found to be 7.98 and 7.11 mg/g respectively at optimum conditions. The pseudo-first-order and pseudo-second-order models were employed for kinetic analysis of adsorption process. The adsorption process follows pseudo-second-order kinetics. The efficacy of the adsorbent in the treatment of effluent from fertilizer factory has been investigated and the results have been found encouraging.

Optically active J-aggregate formed from water-soluble porphyrin with phenylalanine

2012 ◽  
Vol 16 (12) ◽  
pp. 1285-1292 ◽  
Author(s):  
Yoshio Uemori ◽  
Hiroki Munakata ◽  
Sakiko Kitazawa ◽  
Astuko Osada ◽  
Hiroyasu Imai
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Cd Spectroscopy ◽  
Optically Active ◽  
Water Soluble ◽  
Cd Spectra ◽  
Solution Ph ◽  
Chiral Compound ◽  
Water Soluble Porphyrin ◽  
Soret Region

A water-soluble porphyrin bearing multi-dentate ligands was prepared, and its aggregation behavior in solution under various conditions (temperature, pH, metal ion, chiral compound) was investigated using UV-vis absorption spectroscopy, fluorescence spectroscopy, circular dichroism (CD) spectroscopy. Upon the addition of Ca2+, Ba2+ , or Sr2+ to a solution of porphyrin, the porphyrin first forms an H-aggregate and is then transformed to a J-aggregate at 25 °C in buffered aqueous solution (pH 7.4). On the other hand, the porphyrin forms a self-aggregate (H-aggregate) at 25 °C in buffered aqueous solution (pH 6.0), and the H-aggregate does not form the J-aggregate upon the addition of the group II metal ions. The measurement of CD spectra revealed that the H-aggregate that forms right after the addition of Ba2+ to the porphyrin solution in the presence of D- or L-phenylalanine does not show an induced CD signal, while the J-aggregate formed from the H-aggregate shows induced CD signals in the Soret region.

scholarly journals Characterization, Dissolution, and Solubility of Zn-Substituted Hydroxylapatites [(ZnxCa1−x)5(PO4)3OH] at 25°C

2017 ◽  
Vol 2017 ◽  
pp. 1-13
Author(s):  
Xin Zhao ◽  
Yinian Zhu ◽  
Zongqiang Zhu ◽  
Yanpeng Liang ◽  
Yanlong Niu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Lattice Parameter ◽  
Batch Experiment ◽  
Molar Ratio ◽  
Final Solution ◽  
Free Energies ◽  
Solution Ph ◽  
Initial Ph ◽  
Zinc Concentrations ◽  
The Mean

A series of Zn-substituted hydroxylapatites [(ZnxCa1−x)5(PO4)3OH, Zn-Ca-HA] with the Zn/(Zn + Ca) molar ratio (XZn) of 0~0.16 was prepared and characterized, and then the dissolution of the synthesized solids in aqueous solution was investigated by batch experiment. The results indicated that the aqueous zinc, calcium, and phosphate concentrations greatly depended on the Zn/(Zn + Ca) molar ratio of the Zn-Ca-HA solids (XZn). For the Zn-Ca-HA dissolution at 25°C with an initial pH of 2.00, the final solution pH increased, while the final solution calcium and phosphate concentrations decreased with the increasing XZn. The final solution zinc concentrations increased with the increasing XZn when XZn≤0.08 and decreased with the increasing XZn when XZn = 0.08~0.16. The mean Ksp values for (ZnxCa1−x)5(PO4)3OH at 25°C decreased from 10−57.75 to 10−58.59 with the increasing XZn from 0.00 to 0.08 and then increased from 10–58.59 to 10–56.63 with the increasing XZn from 0.08 to 0.16. This tendency was consistent with the dependency of the lattice parameter a on XZn. The corresponding free energies of formation (ΔGfo) increased lineally from −6310.45 kJ/mol to −5979.39 kJ/mol with the increasing XZn from 0.00 to 0.16.

STRUCTURE OF AN ARABOGALACTAN FROM TAMARACK (LARIX LARICINA)

1960 ◽  
Vol 38 (2) ◽  
pp. 280-293 ◽  
Author(s):  
G. A. Adams
Keyword(s):  
Aqueous Solution ◽  
Water Soluble ◽  
Molar Ratio ◽  
Larix Laricina ◽  
Soluble Polysaccharide ◽  
Main Component ◽  
Hydrolysis Of

A water-soluble polysaccharide containing L-arabinose and D-galactose in a molar ratio 1:3.8 was isolated from tamarack. Fractionation with ethanol from aqueous solution yielded one main component which was judged to be homogeneous on the basis of electrophoresis and sedimentation data. Hydrolysis of the fully methylated polysaccharide yielded, 2,3,5-tri-O-methyl-L-arabinose (2 moles); 2,3,4,6-tetra-O-methyl-D-galactose (16 moles); 2,5-di-O-methyl-L-arabinose (5 moles); 2,3,4-tri-O-methyl-L-arabinose (5.5 moles); 2,3,4-tri-O-methyl-D-galactose (11 moles); 2,4,6-tri-O-methyl-D-galactose (3 moles); 2,6-di-O-methyl-D-galactose (1 mole); 2,4-di-O-methyl-D-galactose (20 moles); 2-O-methyl-D-galactose (3 moles).Possible structures for the arabogalactan are proposed and discussed on the basis of these results.

Study on the photostability of water-soluble Zn(II) and Al(III) phthalocyanines in aqueous solution

2010 ◽  
Vol 14 (11) ◽  
pp. 968-974 ◽  
Author(s):  
Nina A. Kuznetsova ◽  
Dmitry A. Makarov ◽  
Olga A. Yuzhakova ◽  
Ludmila I. Solovieva ◽  
Oleg L. Kaliya
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Singlet Oxygen ◽  
Narrow Range ◽  
Water Soluble ◽  
Zinc Phthalocyanine ◽  
Quantum Yields ◽  
Type Ii ◽  
Positively Charged ◽  
Dye Structure

The photodegradation of a series of water-soluble Zn(II) and Al(III) phthalocyanines has been studied in aerobic aqueous solutions. The photobleaching quantum yields of zinc phthalocyanine derivatives range from 2.2 × 10-4 for octacarboxy- to 1.5 × 10-5 for ZnPc , bearing 16 positively charged groups on periphery. Their aluminum counterparts are more photostable and photobleach with quantum yields in the narrow range (0.75 ÷ 2 × 10-6). The pH dependences of the photobleaching quantum yields for aluminum phthalocyanines show enhanced photodegradation for molecules with deprotonated axial H2O ligand. Some aspects of the mechanism of dyes photodegradation were studied and discussed. It was found that contribution to photooxidation of type II pathways depends upon a particular dye structure. Thus, no contribution of singlet oxygen to the photooxidation of cationic phthalocyanines has been found, even though singlet oxygen is involved in the photodegradation of negatively charged phthalocyanines.

Labeling Cells with Silver/Dendrimer Nanocomposites

2004 ◽  
Vol 845 ◽  
Author(s):  
Wojciech Lesniak ◽  
Xiangyang Shi ◽  
Anna Bielinska ◽  
Katarzyna Janczak ◽  
Kai Sun ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Uv Light ◽  
Toxicity Testing ◽  
Water Soluble ◽  
Cell Labeling ◽  
Single Particles ◽  
Experimental Conditions ◽  
Silver Nanocomposite ◽  
Positively Charged

ABSTRACTWe have developed water-soluble, biocompatible, fluorescent, and photostable silver/dendrimer nanocomposites that have a potential to be used for in vitro cell labeling. A PAMAM_E5.NH2 dendrimer was used as a template to prepare first a silver-dendrimer complex in an aqueous solution at biologic pH=7.4. Conversion into nanocomposite was achieved by irradiating the solution of the [(Ag+)25-PAMAM_E5.NH2] complex by UV light to reduce the bound Ag+ to zero-valent Ag0 atoms, which were simultaneously trapped in the dendrimer network. Results indicate that the {(Ag0)25-PAMAM_E5.NH2} silver/dendrimer nanocomposite forms positively charged single particles of 4–5 nm under the experimental conditions used. The dendrimer nanocomposite proved to be fluorescent. Toxicity testing of {(Ag0)25-PAMAM_E5.NH2} nanocomposite revealed a behavior similar to the template dendrimer. Intracellular internalization of the silver nanocomposite and cell labeling capabilities was confirmed by confocal microscopy.

scholarly journals Preparation and characterization of iron-copper binary oxide and its effective removal of antimony(III) from aqueous solution

2016 ◽  
Vol 74 (2) ◽  
pp. 393-401 ◽  
Author(s):  
Yongchao Li ◽  
Bing Geng ◽  
Xiaoxian Hu ◽  
Bozhi Ren ◽  
Andrew S. Hursthouse
Keyword(s):  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Binary Oxide ◽  
Molar Ratio ◽  
Precipitation Process ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
X Ray ◽  
Freundlich Adsorption Isotherm ◽  
Co Precipitation

An Fe-Cu binary oxide was fabricated through a simple co-precipitation process, and was used to remove Sb(III) from aqueous solution. X-ray diffraction, scanning electron microscopy, energy dispersive X-ray and N2 adsorption–desorption measurements demonstrated that the Fe-Cu binary oxide consisted of poorly ordered ferrihydrite and CuO, and its specific surface area was higher than both iron oxide and copper oxide. A comparative test indicated that Fe/Cu molar ratio of prepared binary oxide greatly influenced Sb(III) removal and the optimum Fe/Cu molar ratio was about 3/1. Moreover, a maximum adsorption capacity of 209.23 mg Sb(III)/g Fe-Cu binary oxide at pH 5.0 was obtained. The removal of Sb(III) by Fe-Cu binary oxide followed the Freundlich adsorption isotherm and the pseudo-second-order kinetics in the batch study. The removal of Sb(III) was not sensitive to solution pH. In addition, the release of Fe and Cu ions to water was very low when the pH was greater than 6.0. X-ray photoelectron spectroscopy analysis confirmed that the Sb(III) adsorbed on the surface was not oxidized to Sb(V).

Heterojunction of Hydrophobic Poly(1,4-phenylenevinylene) and Hydrophilic PEDOT:PSS on Hydrophilic CdS Nanoparticles

2008 ◽  
Vol 8 (9) ◽  
pp. 4730-4733 ◽  
Author(s):  
Wonjoo Lee ◽  
Su Jin Baek ◽  
Sun Ki Min ◽  
Gangri Cai ◽  
Joong Ki Lee ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Water Soluble ◽  
Cds Nanoparticles ◽  
Layer By Layer ◽  
Deposition Method ◽  
Water Contact ◽  
Styrene Sulfonate ◽  
Layer Deposition ◽  
Poly Styrene Sulfonate ◽  
Positively Charged

Heterojunction of hydrophobic poly(1,4-phenylenevinylene) (PPV) on hydrophilic CdS nanoparticles was successfully prepared by the multi-layering of poly(p-xylene tetrahydrothiophenium chloride) (pre-PPV: precursor of PPV polymer) and poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT:PSS) in an aqueous solution followed by a thermal treatment. CdS nanoparticles thin films were prepared on tin-doped indium oxide (ITO) by a chemical-bath-deposition method. The CdS surface was hydrophilic with low water contact angle of 15°. Positively charged and water-soluble pre-PPV was used to form multilayers with PEDOT:PSS by a layer-by-layer deposition method. Pre-PPV is easily converted to conjugated PPV polymer by a thermal treatment. The CdS nanoparticles-(PPV/PEDOT:PSS) multilayer films constitute efficient acceptor-sensitizer dyad systems, which generate a photocurrent of 2,660 nA/cm2 under the air mass (AM) 1.5 conditions (I = 100 mW/cm2) for sample with 4.5 bilayers.

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